具有短距离吸引力的颗粒的凝化
Peter J Lu1, Emanuela Zaccarelli, Fabio Ciulla
1Department of Physics, Cambridge, Massachusetts 02138, USA. plu@fas.harvard.edu
Nature
|May 24, 2008
概括
具有短距离吸引力的体系统中的凝是由旋点分解,热力学不稳定性启动的. 这一过程导致密度波动和动态停止的集群,形成凝,并与液态气相分离有关.
科学领域:
- 体和材料科学 材料科学
- 软物质物理学 软物质物理学
- 物理化学 物理化学
背景情况:
- 纳米级和体颗粒显著改变材料特性,通过聚合诱导复杂流体的固体状行为.
- 粒子聚合成介面观集群和网络是由粒子间的吸引力驱动的,导致凝的形成.
- 对于凝的现有理论,包括扩散有限集群聚合 (DLCA),动态停止,相分离,透和干扰,缺乏共识,特别是关于凝相界限.
研究的目的:
- 为了研究基本的机制驱动凝在系统的球形颗粒与同otropic,短距离的吸引力.
- 为了澄清凝和热力学相变之间的关系.
- 建立适用于各种粒子系统的凝的统一理解.
主要方法:
- 在合体系统中对凝动态的实验研究.
- 在受控吸引相互作用下分析粒子聚合和集群形成.
- 实验观测与理论预测和模拟相位分离和透的比较.
主要成果:
- 凝是由旋点分解启动的,热力学不稳定性是由于短距离的吸引力引起的.
- 脊柱的分解会引发密度波动,形成跨度集群,然后动态地停止,形成凝.
- 在所有预测分相的样本中观察到凝,支持凝和平衡液态气相分离之间的直接联系.
结论:
- 具有短距离吸引力的合体系统中的凝结是平衡液态气相分离的直接结果,而不仅仅是动态现象.
- 这些发现表明,相分离,而不是透,是有吸引力的球体模型中化的相关机制.
- 这种凝的统一图像独立于微观细节,并且广泛适用于具有短距离吸引力的粒子系统.
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